Transcript PowerPoint 프레젠테이션

Distributed Generation
Mohammad Amin Latifi
Bureau of Privatization
Ministry of Energy
1
US electric industry as an example
2
Future Trends of Electric Utility Industry
Central Power Plants
Distributed Energy Systems
Photovoltaic Array
Microturbine
Wind Turbine
Fuel Cell
Combustion Gas
Turbines
Energy Storage
Devices
Operating System For DG
Electric Power
Monitoring &
Control Lines
Central Power Station
 Transmission line
Regional Dispatch
Energy Value
Information
Gas turbines
Smart controller
Communication
Distribution
Substation
Micro-turbines
Energy storage
devices
Distribution line
Stand-alone
Remote location
Town
Building
 Source: Distributed Utility Associates
Factory
Hospital
4
Definition
 Distributed
Generation
(DG)
is
the
implementation of various power generating
resources, near the site of need, either for
reducing reliance on, or for feeding power directly
into the grid. DG may also be used to increase
transmission and distribution system reliability.
5
Technologies for DG
 Technologies for Distributed Energy Systems (DG)
 Gas technologies
 Combustion gas turbines
 Micro-turbines
 Fuel cells
 Renewable Energy Technologies
 Biomass power
 Small wind turbines
 Photovoltaic Arrays
6
Applications for DG
 Applications of DG
 Stand-alone
 Standby
 Grid-interconnected
 Peak shaving
7
Benefits of DG
 Benefits of DG
 Environmental-friendly and modular electric generation
 Increased reliability
Fuel flexibility
 Uninterruptible service
 Cost savings
 On-site generation
Standby Generation
8
Value of DG
9
Grid losses Vs. DG penetration level
10
Barriers of DG
 Barriers
 Technical Barriers
 Protective equipment
 Safety measures
 Reliability and power-quality concerns
 Business-Practices Barriers
 Contractual and procedural requirements for interconnection
 Procedures for approving interconnection, application and interconnection fees,
 Insurance requirements
 Operational requirements
 Regulatory Barriers
 Tariff structures applicable to customers
 Net metering
 Environmental permitting
11
What supports Technologies of DG?
 What supports Technologies of DG?
 Power Electronics Technologies
 Advanced Power Converter Design Technique
 High-speed/high-power/low-losses power switches
 New control techniques
 Digital signal processors with high performance
 New communications in the form of the Internet
 Planning and valuation tools
 Value to grid
 Capacity needs assessment
12
Comparison of Several Technologies
Technology
Combustion
Gas Turbine
Micro-turbine
Fuel Cell
Wind Turbine
Photovoltaic
Array
Size
0.5 – 30+MW
25 – 500 kW
1 kW – 10 MW
0.3 kW – +5 MW
0.3 kW -2 MW
Installed
Cost ($/kW)
400 – 1,200
1,200 – 1,700
1,000 – 5,000
1,000 - 5,000
6,000 – 10,000
O&M Cost
($/kWh)
0.003 – 0.008
0.005 – 0.016
0.0019 – 0.0153
0.005
0.001-0.004
Elec.
Efficiency
20 - 45%
20 – 30%
30 – 60%
20 – 40%
5 – 15%
Overall
Efficiency
80 – 90%
80 – 85%
80 – 90%
Fuel Type
natural gas,
biogas, propane
natural gas,
hydrogen, biogas,
propane, diesel
hydrogen, natural
gas, propane
wind
sunlight
 Source: Distributed Energy Resources and Resource Dynamics Corporation
Combustion Gas Turbines (1)
fuel
Power Turbine
air
Combustor
Compressor
Generator
Feed water
Power
Converter
HRSG
(Heat Recovery
Steam Generator)
Process steam
Fig. 1 Block diagram of Combustion Gas Turbine System.
14
Combustion Gas Turbines (2)
 Features
 Very mature technology
 Size: 0.5 – 30+ MW
 Efficiency: electricity (20 – 45%), cogeneration (80 – 90%)
 Installed cost ($/kW): 400 – 1,200
 O&M cost ($/kWh): 0.003 – 0.008
 Fuel: natural gas, biogas, propane
 Emission: approximately 150 – 300 ppm NOx (uncontrolled)
below approximately 6 ppm NOx (controlled)
 Cogeneration: yes (steam)
 Commercial Status: widely available
 Three main components: compressor, combustor, turbine
 Start-up time range: 2 – 5 minutes
 Natural gas pressure range: 160 – 610 psig
 Nominal operating temperature: 59 F
15
Combustion Gas Turbines (3)
 Advantages & Disadvantages
 Advantages
 High efficiency and low cost (particularly in large systems)
 Readily available over a wide range of power output
 Marketing and customer serving channels are well established
 High power-to-weight ratio
 Proven reliability and availability
 Disadvantages
 Reduced efficiencies at part load
 Sensitivity to ambient conditions (temperature, altitude)
 Small system cost and efficiency not as good as larger systems
16
Micro-turbines (1)
17
Micro-turbines (2)
 Features
 Size: 25 – 500 kW
 Efficiency: unrecuperated (15%), recuperated (20 – 30%), with heat recovery (up to 85%)
 Installed cost ($/kW): 1,200 – 1,700
 O&M cost ($/kWh): 0.005 – 0.016
 Fuel: natural gas, hydrogen, biogas, propane, diesel
 Emission: below approximately 9 - 50 ppm NOx
 Cogeneration: yes (50 – 80C water)
 Commercial Status: small volume production, commercial prototypes now
 Rotating speed: 90,000 – 120,000
 Maintenance interval: 5,000 – 8,000 hrs
18
Micro-turbines (3)
 Advantages & Disadvantages
 Advantages
 Small number of moving parts
 Compact size
 Light-weight
 Good efficiencies in cogeneration
 Low emissions
 Can utilize waste fuels
 Long maintenance intervals
 Disadvantages
 Low fuel to electricity efficiencies
19
Fuel Cells (1)
 Electrochemical energy conversion: Hydrogen + Oxygen  Electricity, Water, and Heat
AC Power
Power
Converter

+
Fuel
Reformer
Cathode
Catalyst
H2
O2
from air
Anode
Catalyst
Polymer
Electrolyte
H2O
Exhaust
Fig. 3 Block diagram of Fuel Cell System.
18
20
Fuel Cells (3)
 Features (2)
 Size: 1 kW – 10 MW
 Efficiency: electricity (30 – 60%), cogeneration (80 – 90%)
 Installed cost ($/kW): 1,000 – 5,000
 O&M cost ($/kWh): 0.0019 – 0.0153
 Fuel: natural gas, hydrogen, propane, diesel
 Emission: very low
 Cogeneration: yes (hot water)
 Commercial Status:
 PAFC: commercially available
 SOFC, MCFC, PEMFC: available in 2004
21
Wind Turbines (1)
Nacelle
Wind
Low-speed
shaft
Gear Box
High-speed
shaft
Generator
Power Converter
Fig. 4 Block diagram of Small Wind Turbine System.
22
Wind Turbines (2)
 Features
 Size: small (0.3 - 50 kW), large (300 kW – +5 MW)
 Efficiency: 20 – 40%
 Installed cost ($/kW): large-scale (900 - 1,100), small-scale (2,500 - 5,000)
 O&M cost ($/kWh): 0.005
 Fuel: wind
 Emission: zero
 Other features: various types and sizes
 Commercial Status: widely available
 Wind speed:
 Large turbine: 6 m/s (13 mph) at average sites
 Small turbine: 4 m/s (9 mph) at average sites
 Typical life of a wind turbine: 20 years
23
Wind Turbines (3)
 Advantages & Disadvantages
 Advantages
 Power generated from wind farms can be inexpensive
 Low cost energy
 No harmful emissions
 Minimal land use
: the land below each turbine can be used for animal grazing or farming
 No fuel required
 Disadvantages
 Variable power output due to the fluctuation in wind speed
 Location limited
 Visual impact
: Aesthetic problem of placing them in higher population density areas
 Bird mortality
Photovoltaic Arrays (1)
PV module
Cell
Array
Charge
Controller
AC power
DC power
Batteries
Power Converter
Fig. 5 Block diagram of Photovoltaic Array System.
25
Photovoltaic Arrays (4)
 Features (3)
 Size: 0.3 kW – 2 MW
 Efficiency: 5 – 15%
 Installed cost ($/kW): 6,000 – 10,000
 O&M cost ($/kWh): 0.001
 Fuel: sunlight
 Emission: zero
 Main components: batteries, battery chargers, a backup generator, a controller
 Other features: no moving parts, quiet operation, little maintenance
 Commercial Status: commercially deployed
 An individual photovoltaic cell: 1 – 2 watts
26
Photovoltaic Arrays (5)
 Advantages & Disadvantages
 Advantages
 Work well for remote locations
 Require very little maintenance
 Environmentally friendly (No emissions)
 Disadvantages
 Local weather patterns and sun conditions directly affect the potential of photovoltaic system.
Some locations will not be able to use solar power
27
Energy Storage Technologies
 Batteries
 Capacitors
 Flywheels
 Superconducting Magnetic Energy Storage
 Compressed air energy storage
28
Different Configurations for DG
1. A Power Converter connected
in a Stand-alone AC System (1)
Power Converter
3  AC
240/480 V
50 or 60 Hz
Sensors
Distributed
Energy
System
Trans.
Vdc
Loads
V, I, P, Q
DSP
Controller
Fig. 6 Block diagram of a Power Converter connected
in a stand-alone AC system.
29
Different Configurations for DG
1. A Power Converter connected
in a Stand-alone AC System (2)
I
Vdc
V
E
Load
3  AC
240/480 V
50 or 60 Hz
Fig. 7 Simplified block diagram of Fig. 6.
30
Different Configurations for DG
2. A Power Converter connected
in Parallel with the Utility Mains (1)
Power Converter
Utility
Mains
3  AC
240/480 V
50 or 60 Hz
Sensors
Distributed
Energy
System
Trans.
Vdc
Loads
V, I, P, Q
DSP
Controller
Fig. 8 Block diagram of a Power Converter connected
in parallel with the utility mains.
31
Different Configurations for DG
2. A Power Converter connected
in Parallel with the Utility Mains (2)
Utility
Mains
I
Vdc
V
E
3  AC
240/480 V
50 or 60 Hz
Fig. 9 Simplified block diagram of Fig. 8.
32
Different Configurations for DG
3. Paralleled-Connected Power Converters
in a Stand-alone AC System (1)
Power Converters
Sensors
Micro-turbine
Trans.
DSP
Controller
3  AC
240/480 V
50 or 60 Hz
V, I, P, Q
Loads
Sensors
Trans.
Fuel Cell
DSP
Controller
V, I, P, Q
Fig. 10 Block diagram of Paralleled-Connected Power Converters
in a Stand-alone AC System.
33
Different Configurations for DG
3. Paralleled-Connected Power Converters
in a Stand-alone AC System (2)
I1
V
I2
E
E
V
Vdc1
Vdc2
Loads
Fig. 11 Simplified block diagram of Fig. 10.
34
Different Configurations for DG
4. Paralleled-Connected Power Converters
with a common DC grid in a Stand-alone AC System (1)
Power Converters
Sensors
Micro-turbine
3  AC
240/480 V
50 or 60 Hz
DSP
Controller
V, I, P, Q
Loads
Sensors
Fuel Cell
DC Grid
DSP
Controller
V, I, P, Q
Fig. 12 Block diagram of Paralleled-Connected Power Converters
with a common DC grid in a Stand-alone AC System.
35
Different Configurations for DG
4. Paralleled-Connected Power Converters
with a common DC grid in a Stand-alone AC System (2)
DC Grid
I1
E
Vdc
3  AC
240/480 V
50 or 60 Hz
Loads
I2
E
Fig. 13 Simplified block diagram of Fig. 12.
36
Schematics of an average European electricity
grid and connection levels for DG and RES
37
DG Network Connection Issues
 Impact on power system operation (changing power







flows, voltage profile, uncertainty in power production
and etc)
Voltage regulation
Power losses
Power quality (Sags, swells and etc )
Harmonics
Short circuit levels
Location and size of DG
Safety and protection consideration
38
Voltage regulation example
39
Data needed to evaluate the DG
impact
 Size rating of the proposed DR
 Type of DR power converter (static or rotating machine)
 Type of DR prime energy source (such photovoltaic, wind or fuel







cell
Operating cycles
Fault current contribution of DR
Harmonics output content of DR
DR power factor under various operating conditions
Location of DR on the distribution systems
Locations and setting of voltage regulation equipment on
distribution system
Locations and settings of equipment for over current protection
on distribution system
40
Main Barriers to DG
41
RES Historical Development
42
Distributed Generation (DG) Share of Total
Generation Capacity (2007)
43
44
What is CHP?

Integrated System
 Provides a Portion of the
Electrical Load
 Utilizes the Thermal Energy
 Cooling
 Heating
45
Overview of CHP Technologies
Technology
Pros
Cons
Fuel Cell
- Very low emission
- Exempt from air and permitting in some
areas
- Comes in a complete “ready to connect”
package
- High initial investment
- Limited number of commercially
available units
Gas Turbine
- Excellent service contracts
- Steam generation capabilities
- Mature technology
- Requires air permit
- The size and shape of generator
package is relatively large
Micro-turbine
- Lower initial investment
- High redundancy
- Low maintenance cost
- Relative small size and installation
flexibility
- Relatively new technology
- Requires air permit
- Synchronization problems
possible for large installations
Recip.
Engine
- Low initial investment
- Mature technology
- Relatively small size
- High maintenance costs
- Low redundancy
Benefits of CHP
High Efficiency, On-Site Generation Means





Improved Reliability
Lower Energy Costs
Lower Emissions (including CO2)
Conserve Natural Resources
Support Grid Infrastructure
 Fewer T&D Constraints
 Defer Costly Grid Upgrades
 Price Stability
 Facilitates Deployment of New Clean Energy
Technologies
47
Factors for CHP Suitability
 High Thermal Loads-(Cooling, Heating)
 Cost of buying electric power from the grid versus
to cost of natural gas (Spark Spread)
 Long operating hours (> 3000 hr/yr)
 Need for high power quality and reliability
 Large size building/facility
 Access to Fuels (Natural Gas or Byproducts)
48
Generators
Two Types of Generators
Induction
• Requires Grid Power
Source to Operate
• When Grid Goes
Down, CHP System
Goes Down
• Less Complicated &
Less Costly to
Interconnect
• Preferred by Utilities
Synchronous
• Self Excited (Does
Not Need Grid to
Operate)
• CHP System can
Continue to
Operate thru Grid
Outages
• More Complicated &
Costly to
Interconnect (Safety)
• Preferred by
Customers
49
Efficiency Benefits of CHP
50
Environmental Benefits of CHP (NOx)
51
CO2 Emissions Reductions from CHP
Conventional Generation
Efficiency: 31%
Power St
ation Fu
el
(U.S. Fos
sil Mix)
Power Plant
Combined Heat & Power:
Taurus 65 Gas Turbine
CO2 Emissions
52k Tons/yr
Efficiency: 82.5
%
CHP F
uel (Ga
s)
6.0
MWe
186
117
lb/MMBtu
Lb/MMBtu
Efficiency: 80%
Boiler Fuel (
Gas)
117
Boiler
Lb/MMBtu
Steam
CO2 Emissions
43k Tons/yr
95k Tons
70,000
pph
Steam
CO2 Emissions
56k Tons/yr
…TOTAL ANNUAL CO2 EMISSIONS… 56k Tons
39,000 Tons CO2 Saved/Year
52
CHP and Energy Assurance
Combined Heat & Power (CHP) can Keep Critical Facilities Up &
Operating During Outages
For Example, CHP can Restore Power and Avoid:
– Loss of lights & critical air handling
– Failure of water supply
– Closure of healthcare facilities
– Closure of key businesses
53
Thanks
Any Question?
54